I use an Innocase 2 that I absolutely LOVE but I leave the screen clear of any protectors. I've found after 20 years of using devices with screens (starting with the US Robotics Pilot 1000) that the screen doesn't take that much damage if I take care of the device properly (no keys in pocket with device, don't drop it on rocks, etc). Also, since I've only had the last 5 or 6 phones a year or so, they have all seemed to have retained their smooth and blemish-free screens with a little extra care on my part.
Also, with capacitive screens, the last thing I want to do is put a layer of anything between me and the screen. I love being able to touch the screen ever so lightly and have it immediately register my input.